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Showing results for tags 'leakdown'.
Hi all, EJ251 shortblock, EJ25 D heads, STI gaskets I'm getting an unbalanced shake/hesitation from 1800-2500 rpm. I can't effectively accelerate until rpms are above 2500. Taking off from a stop, the car feels bogged down. Plugs, Wires are less than a year old. Fuel pump/filter/strainer within 6 months. Coil and ignition module are within spec according to an FSM that I read. There was a vacuum leak with the purge solenoid under the intake manifold. It was not operating. Before I found that, my STFT, and LTFT indicated (at idle) 3-10%, and 18-25% respectively. After plugging the vacuum line I have the numbers seen in the photo below. I just did a leak-down test. According to the gauges, I'm within 10% for each cylinder. ALTHOUGH, I do hear/feel air escaping through the intake, and the oil filler tube. I followed this for instructions: I have also done multiple compression tests. For cylinder #3 is 225 psi, the remaining cylinders are between 210 and 215 psi. Can one cylinder being higher than the rest cause an unbalancing/misfire/poor low-end acceleration? Even if the numbers are good, the fact that I have air coming through the oil filler tube and intake, does this suggest the motor is shot? Check my timing again? Is there any change in timing instructions when mating an EJ251 with 25D heads? The heads are closer together, and the bolt holes for the intake manifold needed to be filed down a bit in order to properly bolt it onto the long-block. I've done a smoke test in/around the intake/intake manifold/hoses etc, and don't come up with anything. Thanks for the help, Greg
Thanks as always for the help. Love these forums. On my 1999 Legacy Outback (2.5L DOHC), I recently replaced my timing belt & components after a slipped tooth resulted in poor compression and misfires on cylinders 1 and 3. Before the timing belt replacement I got 90 and 80 psi compression on cylinders 1 and 3, respectively. Now I get 210 and 60 psi respectively. (On cylinders 2 and 4 I got 190 and 180). I detailed this info in this thread. A friend advised a leakdown test next. I put Cylinder 3 in TDC, held it in place with a socket and breaker bar, dialed input pressure up to 75 psi and got 72-73 on the other gauge, i.e. approximately 3-4% leakage. I could hear a quiet hissing through the oil fill cap. 1) Do these numbers seem right---i.e. are the results of my leakdown test consistent with the compression test? Want to make sure I'm doing it right. 2) Assuming it is right, this means I have worn piston rings or cylinder walls, right?